The proposed research will develop a human laboratory preparation to investigate behavioral process critical for understanding the maintences of long-term behavior patterns such as the development, maintences, and resolution of substance abuse. The proposed 4-study research program is aimed at developing and experimental preparation to investigate intertemporal choice behavior in humans which will support future studies that involve choices between drug use and valued non-drug alternatives. Participants will choose between smaller sooner reward (SSRs) versus larger later rewards(LLrs), with white noise reduction (WNR) being used as the reinforce in this initial method development work. Study I will verify that a larger period of WNR is preferred to a shorter one and that an immediate WNR is preferred to a delayed one. Study 2 will define reinforce parameters that generate impulsiveness (i.e., choice of the SSR) in an SSR-LLR choice and preference reversal a constant delay is added to the SSR and LLR. Study 3 will determine if participants exploit and external ( "hard") commitment option to gain access to the LLR. Study 4 will investigate the role of externally unconstrained behavioral patterning ( "soft commitment") in the genesis of self-control.